although this seems not right there should be more to this....
because i thought....
Sin(2x)Sin(x)=Cos(x)
Sin(2x)Sin(x)-Cos(x)=0
2Sin(x)Cos(x)Sin(x)-Cos(x)=0
Cos(x)(2Sin(x)Sin(x))=1
Then Maybe.....
Cos(x)(2Sin(x)Sin(x))=1
Cos(x)=1 and 2Sin(x)=1 and Sin(x)=1